Some existing portable electronic devices accept voice or touch input to control functionality of the devices. For example, a voice command system can map specific verbal commands to operations such as initiating a voice call with a particular contact in response to speaking the contact's name. In another example, a touch input system can map specific touch gestures to operations such as zooming out in response to a pinch gesture on a touch sensitive surface. However, there may be situations where the user's ability to speak a verbal command or perform a touch gesture may be limited.